Which Carb for the Spring

I have quite a hot 360 that I have been swapping carbs between a Holley 600cfm, Road Demon 725 and Holley 3310, 750.

Strickly for street use the 600 cfm vacuum secondary Holley is by far the best choice and is the one that is on my engine the most. The throttle response from 1000-2000 rpm is so much better it make the car much more enjoyable to drive on the street. It does give up power above 5500rpm but again on the street I do not spend much time in that rpm range.

The 3310 750 Holley is very close in throttle response below 2000 rpm and has noticablly more power above 5500 rpm and is still pulling strong at 6500 rpm. I notice you mention the yellow spring. In my engine that is all together to soft. I run the plain spring, even going to the purple I start to get a bog because the secondaries open too fast.

The Road Demon has very bad manners below 1500 rpm to the point that the car is not enjoyable to drive. Once above 2000 it runs as well as the Holley 750. I spent most of last summer trying to get the transition circuits sorted out on this carb to improve the throttle response but never did. BG's tech support was less than helpful and basically told me I purchased the wrong carb and should have gotten a 650 Speed Demon. Since the only difference other than jets between the 650 and 725 is the size of the verturi bowls I asked about purchasing a 650 main body and was basically blown off.

IMHO, If the choice is between a Holley or BG carb I would go with the Holley becuase of the parts and support availability. Even though the BG carb is basically a rehash of a Holley only jets, gaskets, PV and secondary springs are interchangeable.

Also, my Barracuda has run a 13.7@ 120mph with the 600 carb so it really isn't a bad choice. My recomendation regardless of brand is to stay in the 600-650 range.